I was working on some artwork yesterday which involved duplicating groups of objects then applying rotates of either 90 or 180 degrees. For speed I was using rotating using mouse at corner of group and holding down shift to snap to nearest 45 degrees. When I took a good look at the artwork I could see that several (not all) of these groups were not actually at eithr 0, 90 or 180 degrees, but imprecise ones like 180.65 or 90.25 etc. This was enough to make things look skewed. So I did some test with Illustrator. If I inputted a manual rotate transform figure this was absolutely precise. If I zoomed right into the group I was rotating, again this was precise. However when zoomed out to view whole artwork whilst rotating a particular group this was where it could apply odd imprecise rotation amounts. It's like it is some kind of incorrect snapping.
Has anybody else experienced this? I've never noticed this with any previous version of Illustrator.